plandex-ai/plandex · error

error writing file: %v

Error message

error writing file: %v

What it means

WriteCustomModelsFile calls os.WriteFile(path, jsonData, 0644) to persist custom-models.json. This error wraps the OS-level failure of that write — the JSON marshal already succeeded, so the problem is filesystem access or path validity at the Plandex home accounts directory.

Source

Thrown at app/cli/lib/custom_models.go:151

}

func WriteCustomModelsFile(path string, modelsInput *shared.ModelsInput) error {
	err := os.MkdirAll(filepath.Dir(path), 0755)
	if err != nil {
		return fmt.Errorf("error creating directory: %v", err)
	}

	clientModelsInput := modelsInput.ToClientModelsInput()
	clientModelsInput.PrepareUpdate()

	jsonData, err := json.MarshalIndent(clientModelsInput, "", "  ")
	if err != nil {
		return fmt.Errorf("error marshalling models: %v", err)
	}

	err = os.WriteFile(path, jsonData, 0644)
	if err != nil {
		return fmt.Errorf("error writing file: %v", err)
	}

	err = SaveCustomModelsHash(path, modelsInput)
	if err != nil {
		return fmt.Errorf("error saving hash file: %v", err)
	}

	return nil
}

func SaveCustomModelsHash(basePath string, modelsInput *shared.ModelsInput) error {
	hashPath := basePath + ".hash"

	hash, err := modelsInput.Hash()
	if err != nil {
		return fmt.Errorf("error hashing models: %v", err)
	}

View on GitHub (pinned to e2d772072e)

Solutions

1. Check the wrapped error for 'permission denied' and fix ownership/permissions on ~/.plandex/accounts/<userId>/ (e.g. chown -R $USER ~/.plandex).
2. Verify free disk space (df -h) and clear space if the disk is full.
3. Ensure the accounts/<userId> directory exists; recreate it if it was deleted.
4. Avoid running the CLI as root/sudo, which creates root-owned files in the Plandex home dir.

Example fix

// before
sudo plandex models  # creates root-owned custom-models.json
// after
chown -R $(whoami) ~/.plandex
plandex models

// Validate writability before calling
import "os"
func canWrite(path string) bool {
    dir := filepath.Dir(path)
    if _, err := os.Stat(dir); err != nil { return false }
    f, err := os.CreateTemp(dir, ".wtest")
    if err != nil { return false }
    f.Close(); os.Remove(f.Name())
    return true
}
// if !canWrite(path) { fix permissions/space first }

func isWriteError(err error) bool {
    return err != nil && strings.Contains(err.Error(), "error writing file") &&
        !strings.Contains(err.Error(), "hash")
}

if err := lib.WriteCustomModelsFile(path, input); err != nil {
    if isWriteError(err) {
        term.Error("Cannot write custom-models.json: " + err.Error())
        // surface os.* permission/disk hint to the user
        return
    }
    return err
}

When it happens

Trigger: os.WriteFile failing because the target directory (~/.plandex/accounts/<userId>/) does not exist, the disk is full, permissions on the file/directory deny writing, or the path points somewhere unwritable.

Common situations: Read-only home directory or NFS mount; disk quota exceeded; custom-models.json owned by another user after running the CLI with sudo; accounts directory deleted manually.

Understand the failure class

Background: "Permission denied" / "Failed to write" file errors: why a library can't write its files to disk (EACCES, EPERM, ENOSPC) and how to fix them — this error's family across 43 libraries.

Related errors

• failed to write %s: %s
• error writing hash file: %v
• error writing JSON file: %v
• error walking directory: %s
• failed to check if %s exists: %s

AI-assisted analysis of plandex-ai/plandex@e2d772072e (2026-09-05). Data as JSON: /api/errors/21d2f99d20aacabd. Report an issue: GitHub.